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Topic: Cutting keyways without a broach. (Read 3993 times)

I wondered if anyone here has tried cutting a flywheel keyway without a broach by steadily advancing a parting tool through the bore ?

This video shows the kind of thing I mean :-

I'm wanting to fix the flywheel on my current build using something a bit more realistic looking than the usual grubscrew method but don't have any broaches so I have considered trying it. At the moment the flywheel I have is a cast iron 'Lady Stephanie' wheel that is already reamed at 8mm to fit the crankshaft.

I'm probably going to replace the wheel with a better looking one shortly so if I did make a mess then it's not the end of the world but I'd prefer not to damage it if I can.

Peter,If I wasn't on vacation I'd go out in the shop and give you the formula. I used to work at a shop that made gearboxes. Back in the day I did a lot of internal keyways and had it memorized. Wow, that was 22 years ago, no wonder I forgot it. Art

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"The beautiful thing about learning is that no one can take it away from you" B.B. King

How good a fit is the crankshaft in the flywheel bore, if it is a bit looks and you use a tapered key in a straight keyway it may act like a wedge and kick the flywheel off, a matching taper in the hub means the key contacts all the way along and pushes evenly against the hub. 1:100 is the right sort of taper.